1. Field of the Invention
The present invention relates to a data-processing circuit or a video camera. More particularly, the present invention relates to a data-processing circuit or a video camera, for performing a predetermined data process on image data outputted from an imaging device.
The present invention relates also to a data-processing circuit or a video camera. More particularly, the present invention relates to a data-processing circuit or a video camera, for executing a process synchronized with a designated clock frequency on image data of an object scene outputted from an imaging device.
2. Description of the Related Art
According to one example of this type of a circuit or a device, when a solid-state imaging element of 400,000 pixels is attached, a video process is executed according to a clock having a frequency of 14.3 MHz or 28.6 MHz (=14.3 MHz×2). On the other hand, when a solid-state imaging element of 500,000 pixels is attached, a video process is executed according to a clock having a frequency of 18 MHz or 36 MHz (=18 MHz×2). Thereby, it becomes possible to sufficiently reduce a cross-color interference.
However, in the above-described example, there is a need of preparing a clock frequency different depending upon each imaging element, and thus, it is probable that a circuit configuration becomes complicated. Furthermore, as long as the same solid-state imaging element is attached, the clock frequency, which serves as a reference, is fixed to either one of 14.3 MHz or 18 MHz. That is, even when the number of pixels forming a video signal is changed in a middle of the video process, the video signal is processed according to the clock having the same frequency. As a result, in the above-described example, there is a possibility that the circuit scale may not be optimized.
Furthermore, according to another example of this type of a circuit or a device, image data representing an object scene repeatedly captured by an imaging device undergoes a predetermined signal process in a signal-processing circuit, an then, is accommodated in an SDRAM. A video encoder repeatedly reads out one portion of image data belonging to an extraction area, out of image data accommodated in the SDRAM, and drives an LCD monitor based on the read-out image data. The extraction area moves in a manner to compensate a shaking of an imaging surface, and thereby, a shaking of a moving image displayed on the LCD monitor is canceled.
However, a difference between the number of pixels of the image data written to the SDRAM and the number of pixels of the image data read out from the SDRAM is not to reflect on an operation of the signal-processing circuit. Therefore, in the above-described other example, there is a limit to a performance of an image-data process.